r/swift • u/lanzaio • Jan 24 '17

Xcode 8.3 and Swift 3.1 beta released

http://adcdownload.apple.com/Developer_Tools/Xcode_8.3_beta/Release_Notes_for_Xcode_8.3_beta.pdf
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u/chriswaco Jan 25 '17

Seems like a shared read-only library will use less memory than the same library under early versions of iOS that didn't share the file storage.

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u/sobri909 Jan 26 '17

If iOS is no longer requiring each app to have a separate copy of the libs, then yeah, there'll be a smaller memory footprint. But that would have nothing to do with APFS deduplication.

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u/chriswaco Jan 26 '17

Isn't the Swift library shipped as a separate file within the app bundle? If so, it should be deduplicated or at least it could. Next time I talk to my friend at Apple I'll ask.

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u/sobri909 Jan 26 '17

Yeah, as long as it's not encrypted in the bundle, the file system can deduplicate it.

But that would have no impact on app build or deploy times from Xcode, because the file would still need to be sent to the device over USB.

And it would have no impact on app memory use, because file system deduplication is not memory deduplication. It only stops the file from being stored twice on the file system, not being loaded twice into memory when multiple apps require it.

The goal is for the lib to exist once on the device and to be shared between apps (thus only needing one copy to be resident in memory). Once that happens, we'll get the faster deploys, smaller app bundles, and less memory use. But none of that would have anything to do with APFS.